The present invention relates to a refrigerating apparatus. More particularly, the present invention relates to a refrigerating apparatus using an R32 single refrigerant or an R32 mixed refrigerant.
Conventionally, the refrigerating apparatuses are known which include a refrigerant circuit including a compressor, a condenser, a decompressing mechanism and an evaporator, wherein the refrigerant circuit forms a refrigerating cycle using an HCFC-based refrigerant such as R22. Among the components of the refrigerant circuit, the compressor particularly plays an important role in compressing the refrigerant. Therefore, refrigerating machine oil is necessary for smooth operation of the compressor.
In the refrigerating apparatuses using an HFC-based refrigerant, synthetic oil such as ether oil or ester oil compatible with the refrigerant is commonly used as refrigerating machine oil.
As compared to mineral oil used in the conventional refrigerating apparatuses using R22, synthetic oil is more likely to be partially subjected to chemical reaction such as decomposition or polymerization when the air, water or the like is introduced into the refrigerant circuit. As a result, part of the synthetic oil is deposited as sludge in an expansion valve or capillary tube, thereby possibly closing the flow path of the refrigerant circuit.
The air and water are introduced at the time of manufacturing the components of the refrigerant circuit and installing the apparatus at the installation site. In order to reduce the introduced amount thereof, measures must be taken at the time of manufacturing such as changing the manufacturing method or manufacturing process and tightening the quality control. Moreover, at the time of installation, measures must be taken such as improving the achievable vacuum upon vacuuming, extending the vacuuming time, and improving the performance of the vacuum pump.
Accordingly, improved reliability and facilitated handling have been desired for the refrigerating apparatuses using synthetic oil.
The present invention is made in view of the above problems, and it is an object of the present invention to improve reliability of a refrigerating apparatus and facilitate handling thereof.
In order to achieve the aforementioned object, the present invention uses synthetic oil as refrigerating machine oil, and uses a refrigerant having smaller pressure loss than that of a refrigerant such as R22, i.e., an R32 single refrigerant or an R32 mixed refrigerant.
The present invention is made for the following reasons: the R32 single refrigerant or the R32 mixed refrigerant has a greater refrigerating effect than that of R22, R407C or R410A, and therefore the circulation amount of the refrigerant required to obtain the same capability may be smaller than that of a refrigerant such as R22. Accordingly, the R32 single refrigerant or the R32 mixed refrigerant has smaller pressure loss than that of a refrigerant such as R22 when flowing through a flow path with the same diameter.
Refrigerant piping includes liquid piping. For example, the liquid piping is the piping provided between the outlet of the condenser to the inlet of the evaporator. This liquid piping will not cause degradation in performance of the apparatus if increase in pressure loss, if any, is within the control range of the decompressing mechanism (capillary tube, expansion valve and the like). When the R32 single refrigerant or the R32 mixed refrigerant is used, the difference in pressure in the refrigerant circuit is at most about 1.6 times that in the case where R22 is used. The allowable range of the pressure loss of the refrigerant is thus increased accordingly. Therefore, the use of the R32 single registrant or the R32 mixed registrant enables reduction in the diameter of the liquid piping as compared to the conventional examples without degrading the performance of the apparatus.
The refrigerant piping also includes discharge piping and intake piping. For example, the discharge piping is the piping provided between the discharge side of the compressor and the inlet of the condenser, and the intake piping is the piping provided between the outlet of the evaporator and the intake side of the compressor. The pressure loss in the discharge piping and the intake piping significantly affects the performance of the apparatus. However, the use of the R32 single refrigerant or the R32 mixed refrigerant reduces the pressure loss as compared to the conventional examples. Accordingly, even if the discharge piping and the intake piping have a reduced diameter, the use of the R32 single refrigerant or the R32 mixed refrigerant enables the performance of the apparatus to be kept equivalent to that in the conventional examples. Moreover, the R32 single refrigerant or the R32 mixed refrigerant enables slight reduction in pipe diameter while allowing for higher performance than that of the conventional apparatuses.
Regarding a heat exchanger, the difference in saturation temperature corresponding to the pressure loss of the refrigerant is an important factor that affects the performance thereof. The R32 single refrigerant or the R32 mixed refrigerant has small pressure loss. Therefore, the difference in saturation temperature can be made equal to that of the conventional examples even when a heat transfer tube of the heat exchanger has a reduced diameter. Moreover, the R32 single refrigerant or the R32 mixed refrigerant has a higher heat transfer coefficient than that of the conventional examples. Therefore, the heat-exchange capability can be retained at a high level even when the heat transfer tube has a reduced diameter.
From the foregoing description, the inventor found that the use of the R32 single refrigerant or the R32 mixed refrigerant as well as reduction in diameter of the refrigerant piping and the heat transfer tube of the heat exchanger for the purpose of reducing the internal volume of the refrigerant circuit would not be problematic in terms of the performance. The amount of air and water introduced into the refrigerant circuit is increased in proportion to the internal volume of the refrigerant circuit. In the present invention, the internal volume of the refrigerant circuit is reduced by using the R32 single refrigerant or the R32 mixed refrigerant, whereby the amount of air and water introduced into the refrigerant circuit is reduced, preventing degradation of synthetic oil.
More specifically, according to one aspect of the invention, a refrigerating apparatus uses a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32, and uses synthetic oil as refrigerating machine oil.
According to another aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity of 5 kW or less. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 4.75 mm.
According to still another aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity of 5 kW or less. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 3.2 mm to 4.2 mm.
According to yet another aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity of 5 kW or less. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 3.5 mm to 3.9 mm.
According to a further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity of 5 kW or less. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 3.6 mm to 3.8 mm.
According to a still further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 5 kW and equal to or less than 18 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 7.92 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 18 kW and equal to or less than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 11.1 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 5 kw and equal to or less than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 5.4 mm to 7.0 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 5 kW and equal to or less than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 5.7 mm to 6.7 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 5 kw and equal to or less than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 6.0 mm to 6.4 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus being designed to have a rated cooling capacity of more than 22.4 kw. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 13.88 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus being designed to have a rated cooling capacity of more than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 7.5 mm to 9.8 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and. includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus being designed to have a rated cooling capacity of more than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 7.8 mm to 9.5 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus being designed to have a rated cooling capacity of more than 22.4 kW. Liquid piping (32) of the refrigerant circuit (10) is formed from piping having an inner diameter of 8.1 mm to 9.1 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity of 3.2 kW or less. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 7.92 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 3.2 kW and equal to or less than 5 kW. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 11.1 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 5 kW and equal to or less than 9 kW. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 13.88 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 9 kW and equal to or less than 18 kW. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 17.05 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus having a rated cooling capacity that is larger than 18 kW and equal to or less than 22.4 kW. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 23.4 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32 and includes a compressor (11) using synthetic oil as refrigerating machine oil, the refrigerating apparatus being designed to have a rated cooling capacity of more than 22.4 kW. Gas piping (31) of the refrigerant circuit (10) is formed from piping having an inner diameter of less than 26.18 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that includes a compressor (11) using synthetic oil as refrigerating machine oil and an indoor heat exchanger (15), and forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32. A heat transfer tube of the indoor heat exchanger (15) is formed from a heat transfer tube having an inner diameter of less than 5.87 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that includes a compressor (11) using synthetic oil as refrigerating machine oil and an outdoor heat exchanger (13), and forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32. A heat transfer tube of the outdoor heat exchanger (13) is formed from a heat transfer tube having an inner diameter of less than 6.89 mm.
According to a yet further aspect of the invention, a refrigerating apparatus includes a refrigerant circuit (10) that includes a compressor (11) using synthetic oil as refrigerating machine oil and an outdoor heat exchanger (13), and forms a refrigerating cycle using as a refrigerant a single refrigerant of R32 or a mixed refrigerant containing at least 75% by weight of R32. A heat transfer tube of the outdoor heat exchanger (13) is formed from a heat transfer tube having an inner diameter of less than 7.99 mm.
The liquid piping (32) may be liquid connection piping connecting an indoor unit (17) and an outdoor unit (16) to each other.
The gas piping (31) may be gas connection piping connecting an indoor unit (17) and an outdoor unit (16) to each other.
The mixed refrigerant is preferably an R32/R125 mixed refrigerant.
The refrigerant may be a single refrigerant of R32.
According to the present invention, the internal volume of the refrigerant circuit (10) can be reduced, and therefore the amount of air, water or the like that is introduced into the refrigerant circuit (10) can be reduced, enabling improvement in reliability of the apparatus using synthetic oil.
Moreover, since the water or the like is less likely to be introduced into the refrigerant circuit (10), manufacturing and installation can be easily managed, facilitating manufacturing and installation.